US8156672B2 - Stormproof billboard and control method thereof - Google Patents

Abstract

The present invention relates to an stormproof billboard and control method thereof, which includes a column, a billboard stent, a rotating element, a motor, an electromagnetic brake, an anemoscope, a trigger switch, and an electric control assembly, wherein the control element respectively connects with the electromagnetic brake, the motor and the trigger switch, the electric control assembly controls the work of the motor and the electromagnetic brake by the wind speed signal measured by the anemoscope and the signal of the trigger switch. By using above structure, the invention can change the windward section of the stormproof billboard by the wind speed and the wind direction, such that effectively reduces the wind load, makes the stormproof billboard more secure in use. The invention is easy to control and secure to use, makes the advertisement have a good effect, it is worth to use the stormproof billboard.

Description

BACKGROUND OF THE PRESENT INVENTION

1. Field of Invention

The present invention relates to a billboard and control method thereof, and more particularly to a large stormproof billboard and control method thereof.

2. Description of Related Arts

Billboards are used as devices to transmit advertising information to the public, and according to different needs, the billboards can be made into various forms. Among that the large billboards which are established on transport corridors, transport hubs and so on are more common, the billboard stents of the billboards are usually supported on single column or multiple columns, and according to the billboard face, the billboards can be divided into single-faced, double-faced and multiple-faced. Because such billboards have simple structure, easy production process and can attract the attention of passers, the billboards are widely used. However, in actual use, it is found that: because the billboard stents fixed with the column and the billboard face to the public, the billboards can not change windward side with the wind direction after the billboards are set, so that the billboard may be damaged or fall down in bad weather, which does not only bring unnecessary loss to the advertisers and manufacturers, but also brings great security risk to the pedestrians. In order to eliminate such defects, it is tended to increase the size of the column, improve the material of the billboard stent and so on to meet the wind load in windy weather, but this program will obviously increase the manufacture cost of billboard.

Therefore, people design a stormproof billboard, such as a roadside stormproof billboard, according to Chinese patent, Publication No. CN2760701Y, this patent discloses that: an eccentric column is formed by a column and a billboard panel, the billboard panel connects with the column by a shaft lining so as to rotate with respect to each other, a turn restoration assembly is fixed with the billboard panel, the turn restoration assembly comprises two restoring springs symmetrically disposed on two sides of a support shore, two ends of each restoring spring respectively contact with a movable plate and a mounting plate, the top of the support shore fixed with a rotary block held between the two movable plates, two ends of the rotary block are cone. In use, under the wind force, the billboard panel rotates with respect to the column, drives rotary block and compresses the restoring springs to form a torque. When the wind force is reducing, under the force of the restoring springs, the billboard panel is reset, and the torque is released. Clearly, using such billboards can overcome the disadvantage of the conventional billboard to a certain extent. However, after analysing the structure carefully, it is found that: because the billboard panel always rotates with respect to the column and the billboard panel is located on a higher position, even if there is slightest wind, the billboard will rotate, namely, the billboard will deviate from the best direction; when the wind force is reducing, because the billboard panel is heavy, the restoring speed of the billboard panel is slow with only two springs, and when the wind direction changes in a larger scope, the billboard panel has a dead center and therefore can not complete the wide-angle turn. Therefore, in the use of the billboard panel, the billboard can not be in the best direction so that the advertising effectiveness is affected.

And as to an unloading method of the wind load on a billboard and an anti-wind billboard, according to Chinese patent, Publication No. CN100390838C, this patent discloses a control method of the billboard, which uses a wind speed sensor to measure real-time wind speed, an anemoscope translates the wind speed into an electronic control signal, a comparison circuit of the anemoscope compares the electronic control signal with a predetermined control parameter, a motor is controlled by a relay; the motor drives laminas of the louver style billboard panel to adjust an angle by a reduction device and a transmission mechanism. By using the above structure, the windward side of the billboard can be changed to a certain extent for unloading the wind load of the billboard. However, the billboard also has the following shortcoming: first, in control, the control system of the control method simply monitors the real-time wind speed, when the wind speed is greater than the security value and the wind direction is in parallel with the billboard, the system still sends the rotation signal to the laminas of the billboard, but this is unnecessary; and in the process of adjusting laminas angle, because the rigid mechanical drive always exists, the wind load is always transferred to the billboard stent. In bad weather, the wind speed is very unstable, in the process of adjusting laminas, if the wind speed increases instantaneously, the system can not make the corresponding adjustment, the billboard may be damaged by wind. Second, for the mechanical part, because of the louver structure, the movable parts are complex; and because the billboard panel is not a whole, advertise image must be sprayed or consists of plural screens, which makes the image effect bad, maintenance and replacement is also very troublesome.

SUMMARY OF THE PRESENT INVENTION

A main object of the present invention is to provide a stormproof billboard, which can change the windward section of the stormproof billboard by the wind speed, unload the wind load, and reset quickly.

Another object of the present invention is to provide a control method of the stormproof billboard, which can change the windward section of the stormproof billboard by the wind speed, unload the wind load, reset quickly, and make the windward section change in time in the process of resetting.

Another object of the present invention is to provide a control method of the stormproof billboard, which can change the windward section of the stormproof billboard by the wind speed and the wind direction, unload the wind load, reset quickly, and make the windward section change in time in the process of resetting.

Accordingly, in order to accomplish the above object, the present invention provides a stormproof billboard, comprising:

a column, wherein a pedestal is disposed on a top of the column;

a billboard stent, wherein a rotating table is fixed on the billboard stent and corresponding to the pedestal;

a rotating element disposed between the rotating table and the pedestal so as to make the rotating table rotate with respect to the pedestal;

a motor disposed on the column and driving the rotating table to rotate by a driver gear;

an electromagnetic brake disposed on the column to lock the rotating table;

an anemoscope measuring a wind speed;

a trigger switch disposed between the rotating table and the pedestal to measure that whether the rotating table aligns with the pedestal; and

an electric control assembly respectively connecting with the electromagnetic brake, the motor, the anemoscope and the trigger switch, wherein the electric control assembly controls working of the motor and the electromagnetic brake by a signal of the trigger switch and a wind speed signal measured by the anemoscope.

As an improvement, the stormproof billboard further comprises a dogvane, the dogvane connects with the electric control assembly to measure an angle D-value, the angle D-value is a difference value between a billboard stent direction and a natural wind direction, and the electric control assembly controls working of the motor and the electromagnetic brake by the wind speed signal measured by the anemoscope and the signal of the trigger switch.

The rotating table comprises a rotating shaft downwards inserting into the column and disposed on the rotating table, the electromagnetic brake is disposed in the column, the electromagnetic brake comprises a braked wheel ringing on the rotating shaft, a left friction plate disposed on a left side of the braked wheel, and a right friction plate disposed on a right side of the braked wheel, wherein one end of each of the left friction plate and the right friction plate is fixed on an inside wall of the column respectively, another end of each of the left friction plate and the right friction plate is free, a spring is disposed between the two free ends, and at least an electromagnetic power unit is disposed on the free end of the left friction plate or the right friction plate. Of course, the electric control assembly can also be fixed outside the column, to brake a high speed shaft of the driver gear on demand, this embodiment can also control the rotating table to rotate.

A center current collector is disposed in the column, the center current collector comprises three electric elastic clips, and a collecting ring fixed on a tail of the rotating shaft, wherein two carbon brushes are respectively fixed on two relative ends of each elastic clip, three electric annular grooves are spacedly formed on the collecting ring and are mutually insulating, each electric annular groove of the collecting ring is clipped by the corresponding elastic clip to make the carbon brushes cling to an outside surface of the electric annular groove. Clearly, when the rotating table is rotated with the motor, an illumination wire connecting with the elastic clip does not move so as to effectively avoid damaging the illumination wire in the rotating process of the rotating table, such that a circuit is reliable turn-on when the billboard stent is rotating.

As considering to trigger a signal in time after the billboard resets, the trigger switch is disposed between the rotating table and the pedestal, here, the trigger switch consists of a block and a limit switch, wherein the block is fixed on the rotating table, the limit switch can use a conventional travel switch, also can use a dry-reed switch, photoelectric switch or inductive switch, when the rotating table is located on a predetermined position, the limit switch sends the signal to the electric control assembly so as to control the motor stalling or control the electromagnetic brake locking.

The electric control assembly comprises a control element and a signal conversion element, wherein the control element respectively connects with the electromagnetic brake, the motor and the trigger switch, the anemoscope connects with the control element by the signal conversion element, the electric control assembly controls working of the motor and the electromagnetic brake by the wind speed signal measured by the anemoscope and the signal of the trigger switch.

In order to make the billboard stent in parallel with the natural wind in shortest time, the stormproof billboard further comprises a forward relay controlling the motor to rotate forward and a backward relay controlling the motor to rotate backward.

In order to prevent the rotating element contacting with dust and prevent lubricant grease of the rotating element leaking, a sealing element is positioned on a side of the rotating element and is disposed between the pedestal and the rotating table.

In order to accomplish the above object, the present invention provides a control method of the stormproof billboard, comprising the following steps of:

(11) predetermining a first secure wind speed, a second secure wind speed which is less than the first secure wind speed, and a delay time;

(12) the electric control assembly begins to collect a first wind speed measured by the anemoscope;

(13) judging whether the first wind speed is greater than or equal to the first secure wind speed, if not, returning to the step (12); if yes, the electric control assembly sends a control signal to turn on the electromagnetic brake, such that the electromagnetic brake gets power and releases the rotating table so as to make the billboard stent rotate with the natural wind, then entering the next step;

(14) the electric control assembly begins to collect a second wind speed measured by the anemoscope;

(15) judging whether the second wind speed is greater than or equal to the first secure wind speed, if yes, returning to the step (14); if not, entering the next step;

(16) judging whether the second wind speed is less than the second secure wind speed, if not, returning to the step (14); if yes, turning on an inner timer which has been predetermined with the delay time, then entering the next step;

(17) the electric control assembly begins to collect a third wind speed measured by the anemoscope;

(18) judging whether the third wind speed is less than the second secure wind speed, if not, returning to the step (14); if yes, judging whether the timer has expired, if not, returning to the step (17), if yes, entering the next step; and

(19) judging whether the electric control assembly has received the control signal from the trigger switch, wherein the trigger switch will send the control signal to the electric control assembly when the rotating table has aligned with the pedestal, if not, the electric control assembly continues sending the control signal to turn on the electromagnetic brake and the motor, such that the electromagnetic brake continues to release the rotating table so as to make the billboard stent reset by the drive of the motor; if yes, the electric control assembly sends the control signal to make the electromagnetic brake and the motor lose power so as to make the electromagnetic brake lock the billboard stent, returning to the step (12).

In order to accomplish the above object, as an alternatively embodiment, the present invention provides a control method of the stormproof billboard, comprising the following steps of:

(21) predetermining a first secure wind speed, a second secure wind speed which is less than the first secure wind speed, a delay time, and an angle-sine translation table stored in the electric control assembly;

(22) the electric control assembly begins to collect a first wind speed measured by the anemoscope;

(23) judging whether the first wind speed is less than the second secure wind speed, if not, entering the step (26); if yes, turning on an inner timer which has been predetermined with the delay time, then entering the next step;

(24) the electric control assembly begins to collect a second wind speed measured by the anemoscope; judging whether the second wind speed is less than the second secure wind speed, if not, the electric control assembly sends the control signal to make the motor lose power, entering the step (26); if yes, judging whether the timer has expired, if not, returning to the step (24), if yes, entering the next step;

(25) judging whether the electric control assembly has received the control signal from the trigger switch, wherein the trigger switch will send the control signal to the electric control assembly when the rotating table has aligned with the pedestal, if not, the electric control assembly sends the control signal to turn on the electromagnetic brake and the motor, resetting the timer, the timer is returned to zero, and returning to the step (24); if yes, the electric control assembly sends the control signal to make the electromagnetic brake and the motor lose power so as to make the electromagnetic brake lock the rotating table, returning to the step (22);

(26) the electric control assembly begins to collect a first angle D-value measured by the dogvane, wherein the first angle D-value is a difference value between the billboard stent direction and the natural wind direction, looking up the sine value of the first angle D-value, the sine value multiplied by the wind speed is a positive wind speed which vertically forces on the billboard stent, judging whether the positive wind speed which vertically forces on the billboard stent is greater than or equal to the first secure wind speed; if yes, the electric control assembly sends the control signal to turn on the electromagnetic brake, entering the next step; if not, returning to the step (22); and

(27) the electric control assembly begins to collect a second angle D-value measured by the dogvane, wherein the second angle D-value is a difference value between the billboard stent direction and the natural wind direction, judging whether the second angle D-value is zero, if yes, the electric control assembly sends the control signal to turn off the electromagnetic brake, then returning to the step (22); if not, returning to the step (27).

In order to accomplish the above object, as an alternatively embodiment, the present invention provides a control method of the stormproof billboard, comprising the following steps of:

(31) predetermining an object wind direction scope, a plural continuous design wind direction scope which is greater than the object wind direction scope, a secure wind speed corresponding to each design wind direction scope, a maximal secure wind speed which is less than each secure wind speed, and a delay time;

(32) the electric control assembly begins to collect a first wind speed measured by the anemoscope;

(33) judging whether the first wind speed is less than the maximal secure wind speed, if not, entering the step (36); if yes, turning on an timer which has been predetermined with the delay time, then entering the next step;

(34) the electric control assembly begins to collect a second wind speed measured by the anemoscope; judging whether the second wind speed is less than the maximal secure wind speed, if not, the electric control assembly sends the control signal to make the motor lose power, entering the step (36); if yes, judging whether the timer has expired, if not, returning to the step (34), if yes, entering the next step;

(35) judging whether the trigger switch is open, namely, wherein the electric control assembly has received the control signal from the trigger switch, wherein the trigger switch will send the control signal to the electric control assembly when the rotating table has aligned with the pedestal, if not, the electric control assembly sends the control signal to turn on the electromagnetic brake, the forward relay and the backward relay, such that the electromagnetic brake gets power and releases the rotating table so as to make the billboard stent reset under the drive of the motor, resetting the timer, the timer is returned to zero, and returning to the step (34); if yes, the electric control assembly sends the control signal to make the electromagnetic brake and the motor lose power, returning to the step (32);

(36) the electric control assembly begins to collect a first angle D-value, comparing the first angle D-value with the object wind direction scope, if the first angle D-value is in the object wind direction scope, the electric control assembly sends the control signal to turn off the electromagnetic brake, such that the electromagnetic brake loses power to lock the rotating table, and returning to the step (32); and

(37) if the first angle D-value is in the design wind direction scope, the first wind speed is greater than or equal to the secure wind speed corresponding to the design wind direction scope, and the first angle D-value is in 0°˜90° or 180°˜270°, the electric control assembly sends the control signal to turn on the electromagnetic brake, such that the electromagnetic brake gets power and releases the rotating table, and the electric control assembly sends the control signal to turn on the forward relay, such that the billboard stent rotates along the natural wind direction by the drive of the motor, the electric control assembly goes on collecting a second angle D-value until the second angle D-value is 0° or 180°, the motor and the electromagnetic brake are turned off, returning to the step (32); if the first wind speed is greater than or equal to the secure wind speed corresponding to the design wind direction scope, and the first angle D-value is in 90°˜180° or 270°˜360°, the electric control assembly sends the control signal to turn on the electromagnetic brake, such that electromagnetic brake gets power and releases the rotating table, and the electric control assembly sends the control signal to turn on the backward relay, such that the billboard stent also rotates along the natural wind direction by the drive of the motor, the electric control assembly goes on collecting a second angle D-value until the second angle D-value is 0° or 180°, the motor and the electromagnetic brake are turned off, returning to the step (32).

Comparing with the related arts, the invention skillfully increases a motor and an electromagnetic brake to brake or lock the billboard stent, the stormproof billboard can change the windward section of the stormproof billboard by the wind speed measured by the anemoscope or the dogvane, unload the wind load, be used more securely, reset quickly by the motor when the real-time wind speed is less than the predetermined value in a certain time so as to make the billboard stent in the best direction, and can make the windward section change in time in the process of resetting.

These and other objectives, features, and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a structural schematic view of a stormproof billboard according to a first preferred embodiment of the present invention.

FIG. 2 is an enlarged schematic view of the stormproof billboard without the billboard stent, the motor and the driver gear, according toFIG. 1.

FIG. 3 is a structural schematic view of A direction of the electromagnetic brake according toFIG. 2.

FIG. 4 is a top view of the center current collector according toFIG. 2.

FIG. 5 is a partial structural schematic view of B direction ofFIG. 2.

FIG. 6 is a circuit diagram of the electric control assembly according to the first preferred embodiment of the present invention.

FIG. 7 is a flow chart of the control method according to the first preferred embodiment of the present invention.

FIG. 8 is a circuit diagram of the electric control assembly according to a second preferred embodiment of the present invention.

FIG. 9 is a flow chart of the control method according to the second preferred embodiment of the present invention.

FIG. 10 is a circuit diagram of the electric control assembly according to a third preferred embodiment of the present invention.

FIG. 11 is a flow chart of the control method according to the third preferred embodiment of the present invention.

FIG. 12 is a structural schematic view of the stormproof billboard according to a fourth preferred embodiment of the present invention.

FIG. 13 is a structural schematic view of the stormproof billboard according to a fifth preferred embodiment of the present invention.

FIG. 14 is an enlarged schematic view of the stormproof billboard without the billboard stent, the motor and the driver gear, according toFIG. 13.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Further detailed description of the invention with reference to the drawings is made below.

A first preferred embodiment of the present invention illustrates a stormproof billboard and control method thereof, as shown inFIG. 1 toFIG. 5, the stormproof billboard comprises acolumn1, abillboard stent2, anelectromagnetic brake3, amotor4, a centercurrent collector5, ananemoscope6, arotating element7, a trigger switch and an electric control assembly.

Wherein, thecolumn1 uses a hollow tubular body, a bottom of thecolumn1 is based on the ground by foundation as usual, apedestal11 is fixed on a top of thecolumn1, in this embodiment, thepedestal11 uses a platform structure.

Thebillboard stent2 uses a conventional structure which may be symmetrical or eccentric. The stormproof billboard can be double-faced or three-faced, in this embodiment, the stormproof billboard is single-faced. A rotating table21 corresponding to thepedestal11 is fixed on a middle of thebillboard stent2, therotating element7 is disposed between the rotating table21 and thepedestal11, namely, therotating element7 is disposed between a lower surface of the rotating table21 and an upper surface of thepedestal11, the rotating table21 is held by thepedestal11. Arotating shaft211 downwards inserting into thecolumn1 is disposed on the lower surface of the rotating table21.

Theelectromagnetic brake3 is disposed in thecolumn1, as shown inFIG. 2 andFIG. 3, theelectromagnetic brake3 comprises a brakedwheel31 ringing on therotating shaft211, aleft friction plate32 disposed on the left side of the brakedwheel31, and aright friction plate33 disposed on the right side of the brakedwheel31, wherein one end of each of the left andright friction plate32,33 is fixed on an inside wall of thecolumn1 respectively. Another end of each of the left andright friction plate32,33 is free, and twoelectromagnetic power units35 are respectively disposed on the free ends of the left andright friction plate32,33.

Themotor4 is fixed on an outside wall of thecolumn1, an output shaft of themotor4 links with the rotating table21 through aspeed reducer8 and adriver gear9, wherein thespeed reducer8 uses a conventional structure, thedriver gear9 uses sprocket-chain, namely, the rotating table21 uses a sprocket structure, such thatmotor4 is capable of driving the rotating table21 to rotate through the deceleration of thespeed reducer8 and the drive of the sprocket-chain so as to drive the billboard to rotate.

Theelectromagnetic brake3 also can be mounted on the output shaft of thespeed reducer8, and therefore can also make the rotating table21 lock or release.

The centercurrent collector5 is used to protect an illumination wire which is provided to the stormproof billboard, the centercurrent collector5 is disposed in thecolumn1, as shown inFIG. 1,FIG. 2 andFIG. 4, the centercurrent collector5 comprises three electricelastic clips51, and a collectingring52 fixed on a tail of therotating shaft211, wherein two carbon brushes53 are respectively fixed on two relative ends of eachelastic clip51, three electricannular grooves521 are spacedly formed on the collectingring52 and are mutually insulating, each electricannular groove521 of the collectingring52 is clipped by the correspondingelastic clip51 to make the carbon brushes53 cling to an outside surface of the electricannular groove521. Clearly, when the rotating table21 is rotated with themotor4, the illumination wire connecting with theelastic clip51 does not move so as to effectively avoid damaging the illumination wire in the rotating process of the rotating table21, such that the circuit is reliable turn-on when thebillboard stent2 is rotating.

Theanemoscope6 can be based on the ground to monitor a real-time wind speed and sends a wind speed signal to the electric control assembly, theanemoscope6 also can mounted on thebillboard stent2.

As considering to trigger a signal in time after the billboard resets, the trigger switch is disposed between the rotating table21 and thepedestal11, here, the trigger switch consists of ablock20 and alimit switch30, as shown inFIG. 2 andFIG. 5, wherein theblock20 is fixed on the rotating table21, thelimit switch30 can use a conventional travel switch, also can use a dry-reed switch, photoelectric switch or inductive switch, when the rotating table21 is located on a predetermined position, thelimit switch30 sends the signal to the electric control assembly so as to control themotor4 stalling or control theelectromagnetic brake3 locking.

The electric control assembly comprises acontrol element101 and asignal conversion element102, as shown inFIG. 6, wherein thecontrol element101 respectively connects with theelectromagnetic brake3, themotor4 and the trigger switch, theanemoscope6 connects with thecontrol element101 by thesignal conversion element102, the electric control assembly controls working of themotor4 and theelectromagnetic brake3 by the wind speed signal measured by theanemoscope6 and the signal of the trigger switch.

In this embodiment, thecontrol element101 is microprocessor chip NO. 8051, the P1.1 pin of the microprocessor chip connects with the trigger switch; the P1.2 pin of the microprocessor chip connects with an electromagnet of theelectromagnetic brake3; the P0.0-P0.7, P3.6, P1.0, P3.7 pin of the microprocessor chip connect with thesignal conversion element102.

Thesignal conversion element102 consists of a convertor NO. ADC0809, a first inverter, a second inverter, a first AND gate chip, and a second AND gate chip, theanemoscope6 connects with an IN0 input pin of the convertor, the D0.0-D0.7 pin of the convertor respectively connect with P0.0-P0.7 pin of the microprocessor chip, the P3.6 pin of microprocessor chip connects with one input port of the first AND gate chip through the first inverter, the P1.0 pin of the microprocessor chip connects with another input port of the first AND gate chip, an output port of the first AND gate chip connects with the SC, ALE pin of the convertor, the P3.7 pin of the microprocessor chip connects with one input port of the second AND gate chip through the second inverter, the P1.0 pin of the microprocessor chip connects with another input port of the second AND gate chip, an output port of the second AND gate chip connects with the OE pin of the convertor.

In this embodiment, as shown inFIG. 7, a control method of the stormproof billboard comprises the following steps of:

(11) predetermining a first secure wind speed, a second secure wind speed which is less than the first secure wind speed, and a delay time;

(12) the electric control assembly begins to collect a first wind speed measured by theanemoscope6;

(13) judging whether the first wind speed is greater than or equal to the first secure wind speed, if not, returning to the step (12); if yes, the electric control assembly send a control signal to turn on theelectromagnetic brake3, such that theelectromagnetic brake3 gets power and releases the rotating table21 so as to make thebillboard stent2 rotate with the natural wind, then entering the next step;

(14) the electric control assembly begins to collect a second wind speed measured by theanemoscope6;

(15) judging whether the second wind speed is greater than or equal to the first secure wind speed, if yes, returning to the step (14); if not, entering the next step;

(16) judging whether the second wind speed is less than the second secure wind speed, if not, returning to the step (14); if yes, turning on an inner timer which has been predetermined with the delay time, then entering the next step;

(17) the electric control assembly begins to collect a third wind speed measured by theanemoscope6;

(18) judging whether the third wind speed is less than the second secure wind speed, if not, returning to the step (14); if yes, judging whether the timer has expired, if not, returning to the step (17), if yes, entering the next step; and

(19) judging whether the electric control assembly has received the control signal from the trigger switch, wherein the trigger switch will send the control signal to the electric control assembly when the rotating table21 has aligned with thepedestal11, if not, the electric control assembly continues sending the control signal to turn on theelectromagnetic brake3 and themotor4, such that theelectromagnetic brake3 continues to release the rotating table21 so as to make thebillboard stent2 reset by the drive of themotor4; if yes, the electric control assembly sends the control signal to make theelectromagnetic brake3 and themotor4 lose power so as to make theelectromagnetic brake3 lock thebillboard stent2, returning to the step (12).

In use, in normal weather, the left andright friction plate32,33 lock the brakedwheel31 under the force of thespring34, namely, therotating shaft211 is in a locking condition, at this time, thebillboard stent2 faces to people and is locked in a best condition. In windy weather, in order to avoid damaging thebillboard stent2 under the large force of the wind, if the wind speed measured by the electric control assembly is greater than the first secure wind speed, the electric control assembly makes theelectromagnetic brake3 get power so as to make thebillboard stent2 rotate with the wind and automatically adjust to a secure condition; in the delay time, if the wind speed measured by the electric control assembly is less than the second secure wind speed, the electric control assembly makes themotor4 get power so as to make thebillboard stent2 reset under the drive of themotor4, when thebillboard stent2 rotates to a position of the trigger switch, the electric control assembly sends the control signal to make themotor4 and theelectromagnetic brake3 lose power so as to lock thebillboard stent2, such that thebillboard stent2 faces to a better direction again, namely, thebillboard stent2 faces to the road direction.

In a second preferred embodiment of the present invention, with respect to the first preferred embodiment, the stormproof billboard further comprises a dogvane, theanemoscope6 and the dogvane are different measure elements, the second preferred embodiment uses an anemoclinograph collecting the wind speed and the wind direction, wherein the anemoclinograph can be based on the ground to monitor the real-time wind speed and direction, and sends a wind speed and direction signal to the electric control assembly, the anemoclinograph also can be mounted on thebillboard stent2, the electric control assembly controls themotor4 and theelectromagnetic brake3 by the control signal of the trigger switch and the wind speed and direction signal collected by the anemoclinograph.

The dogvane of the anemoclinograph connects with the first input IN0 pin of the convertor, theanemoscope6 of the anemoclinograph connects with a second input IN7 pin of the convertor, as shown inFIG. 8.

Thecontrol element101 also is microprocessor chip NO. 8051, the P1.1, P1.2, P1.3 pin of the microprocessor chip respectively connect with the A, B, C pin of the convertor; the P1.4 pin of the microprocessor chip connects with the trigger switch; the P1.5 pin of the microprocessor chip connects with the electromagnet of theelectromagnetic brake3; the P1.6 pin of the microprocessor chip connects with themotor4.

In second preferred embodiment, as shown inFIG. 9, a control method of the stormproof billboard comprises the following steps of:

(21) predetermining a first secure wind speed, a second secure wind speed which is less than the first secure wind speed, a delay time, and an angle-sine translation table stored in the electric control assembly;

(22) the electric control assembly begins to collect a first wind speed measured by theanemoscope6;

(23) judging whether the first wind speed is less than the second secure wind speed, if not, entering the step (26); if yes, turning on an inner timer which has been predetermined with the delay time, then entering the next step;

(24) the electric control assembly begins to collect a second wind speed measured by theanemoscope6; judging whether the second wind speed is less than the second secure wind speed, if not, the electric control assembly sends the control signal to make themotor4 lose power, entering the step (26); if yes, judging whether the timer has expired, if not, returning to the step (24), if yes, entering the next step;

(25) judging whether the electric control assembly has received the control signal from the trigger switch, wherein the trigger switch will send the control signal to the electric control assembly when the rotating table21 has aligned with thepedestal11, if not, the electric control assembly sends the control signal to turn on theelectromagnetic brake3 and themotor4, resetting the timer, the timer is returned to zero, and returning to the step (24); if yes, the electric control assembly sends the control signal to make theelectromagnetic brake3 and themotor4 lose power so as to make theelectromagnetic brake3 lock the rotating table21, returning to the step (22);

(26) the electric control assembly begins to collect a first angle D-value measured by the dogvane, wherein the first angle D-value is a difference value between thebillboard stent2 direction and the natural wind direction, looking up the sine value of the first angle D-value, the sine value multiplied by the wind speed is a positive wind speed which vertically forces on thebillboard stent2, judging whether the positive wind speed which vertically forces on thebillboard stent2 is greater than or equal to the first secure wind speed; if yes, the electric control assembly sends the control signal to turn on theelectromagnetic brake3, entering the next step; if not, returning to the step (22); and

(27) the electric control assembly begins to collect a second angle D-value measured by the dogvane, wherein the second angle D-value is a difference value between thebillboard stent2 direction and the natural wind direction, judging whether the second angle D-value is zero, if yes, the electric control assembly sends the control signal to turn off theelectromagnetic brake3, then returning to the step (22); if not, returning to the step (27).

Similarly, in use, in normal weather, the left andright friction plate32,33 lock the brakedwheel31 under the force of thespring34, namely, therotating shaft211 is in a locking condition, at this time, thebillboard stent2 faces to people and is locked in a best condition. In windy weather, in order to avoid damaging thebillboard stent2 under the large force of the wind, if the sine value of the wind speed measured by the electric control assembly is greater than the first secure wind speed, the electric control assembly makes theelectromagnetic brake3 get power so as to make thebillboard stent2 rotate with the wind, a period of time later, if the angle D-value is zero, this shows that thebillboard stent2 is in a secure condition; in the delay time, if the sine value of the wind speed measured by the electric control assembly is less than the second secure wind speed, the electric control assembly makes themotor4 get power so as to make thebillboard stent2 reset under the drive of themotor4, when thebillboard stent2 rotates to the position of the trigger switch, the electric control assembly sends the control signal to make themotor4 and theelectromagnetic brake3 lose power so as to lock thebillboard stent2, such that thebillboard stent2 faces to a better direction again, namely, thebillboard stent2 faces to the road direction.

Above control method is adapted for eccentric structure, namely, the rotating table21 is not disposed on the middle of thebillboard stent2, but deviates from thebillboard stent2 in left or right, because this structure makes two sides of thebillboard stent2 uniform, above control method is more reasonable to theeccentric billboard stent2.

In a third preferred embodiment of the present invention, with respect to the second preferred embodiment, the stormproof billboard further comprises aforward relay42 making themotor4 to rotate forward and a backward relay41 making themotor4 to rotate backward, as shown inFIG. 10.

The P1.5 pin of the microprocessor chip connects with the electromagnet of theelectromagnetic brake3; the P2.0 pin of the microprocessor chip connects with theforward relay42; the P2.1 pin of the microprocessor chip connects with the backward relay41; theforward relay42 and the backward relay41 respectively connect with themotor4.

In third preferred embodiment, as shown inFIG. 11, a control method of the stormproof billboard comprises the follow steps of:

(31) predetermining an object wind direction scope, a plural continuous design wind direction scope which is greater than the object wind direction scope, a secure wind speed corresponding to each design wind direction scope, a maximal secure wind speed which is less than each secure wind speed, and a delay time;

(32) the electric control assembly begins to collect a first wind speed measured by theanemoscope6;

(33) judging whether the first wind speed is less than the maximal secure wind speed, if not, entering the step (36); if yes, turning on an timer which has been predetermined with the delay time, then entering the next step;

(34) the electric control assembly begins to collect a second wind speed measured by theanemoscope6; judging whether the second wind speed is less than the maximal secure wind speed, if not, the electric control assembly sends the control signal to make themotor4 lose power, entering the step (36); if yes, judging whether the timer has expired, if not, returning to the step (34), if yes, entering the next step;

(35) judging whether the trigger switch is open, namely, the electric control assembly has received the control signal from the trigger switch, wherein the trigger switch will send the control signal to the electric control assembly when the rotating table21 has aligned with thepedestal11, if not, the electric control assembly sends the control signal to turn on theelectromagnetic brake3, theforward relay42 and the backward relay41, such that theelectromagnetic brake3 gets power and releases the rotating table21 so as to make thebillboard stent2 reset under the drive of themotor4, resetting the timer, the timer is returned to zero, and returning to the step (34); if yes, the electric control assembly sends the control signal to make theelectromagnetic brake3 and themotor4 lose power, returning to the step (32);

(36) the electric control assembly begins to collect a first angle D-value, comparing the first angle D-value with the object wind direction scope, if the first angle D-value is in the object wind direction scope, the electric control assembly sends the control signal to turn off theelectromagnetic brake3, such that theelectromagnetic brake3 loses power to lock the rotating table21, and returning to the step (32); and

(37) if the first angle D-value is in the design wind direction scope, the first wind speed is greater than or equal to the secure wind speed corresponding to the design wind direction scope, and the first angle D-value is in 0°˜90° or 180°˜270°, the electric control assembly sends the control signal to turn on the electromagnetic brake3, such that electromagnetic brake3 gets power and releases the rotating table21, and the electric control assembly sends the control signal to turn on the forward relay42, such that the billboard stent2 rotates along the natural wind direction by the drive of the motor4, the electric control assembly goes on collecting a second angle D-value until the second angle D-value is 0° or 180°, the motor4 and the electromagnetic brake3 are turned off, returning to the step (32); if the first wind speed is greater than or equal to the secure wind speed corresponding to the design wind direction scope, and the first angle D-value is in 90°˜180° or 270°˜360°, the electric control assembly sends the control signal to turn on the electromagnetic brake3, such that the electromagnetic brake3 gets power and releases the rotating table21, and the electric control assembly sends the control signal to turn on the backward relay41, such that the billboard stent2 also rotates along the natural wind direction by the drive of the motor4, the electric control assembly goes on collecting a second angle D-value until the second angle D-value is 0° or 180°, the motor4 and the electromagnetic brake3 are turned off, returning to the step (32).

When thebillboard stent2 is in the best condition, the object wind direction scope is 337.5°˜360°, 0°˜22.5° or 157.5°˜202.5°, at this time, thebillboard stent2 is almost in parallel with the wind direction.

Here, the design wind direction scope is plural, this embodiment has six:

the wind direction scope of A is 22.5°-67.5°, the wind speed should not exceed II (28 m/s);

the wind direction scope of B is 67.5°-112.5°, the wind speed should not exceed I (21 m/s);

the wind direction scope of C 112.5°-157.5°, the wind speed should not exceed II (28 m/s);

the wind direction scope of D 202.5°-247.5°, the wind speed should not exceed II (28 m/s);

the wind direction scope of E 247.5°-292.5°, the wind speed should not exceed I (21 m/s);

the wind direction scope of F 292.5°-337.5°, wind speed should not exceed II (28 m/s).

Similarly, in use, in normal weather, the left andright friction plate32,33 lock the brakedwheel31, at this time, thebillboard stent2 faces to people and is locked in a best condition. In windy weather, if the electric control assembly detects that the angle D-value is in the predetermined object wind direction scope, the direction of the billboard stent2 is almost in parallel with the natural wind direction, the billboard stent2 suffers little force, at this time, the billboard stent2 does not rotate; if the electric control assembly detects that the angle D-value is in the design wind direction scope, and the wind speed is greater than the secure wind speed corresponding to the design wind direction scope, the electric control assembly makes the electromagnet of the electromagnetic brake3 get power, such that the billboard stent2 rotates under the drive of the motor4, if the electric control assembly detects that the angle D-value is 0° or 180°, this shows that billboard stent2 is in a more secure condition; in the delay time, if the wind speed measured by the electric control assembly is less than the maximal secure wind speed, the electric control assembly makes the motor4 get power so as to make the billboard stent2 reset under the drive of the motor4, when the billboard stent2 rotates to the position of the trigger switch, the electric control assembly sends the control signal to make the motor4 and the electromagnetic brake3 lose power so as to lock the billboard stent2, such that the billboard stent2 faces to a better direction again, namely, the billboard stent2 faces to the road direction.

Above control method is adapted for symmetrical structure, namely, the rotating table21 is disposed on the middle of thebillboard stent2.

In a fourth preferred embodiment of the present invention, as shown inFIG. 12, as comparing to the first, second and third preferred embodiment, themotor4 and thespeed reducer8 are also fixed on the inside wall of thecolumn1, the output shaft of themotor4 links with therotating shaft211 by thespeed reducer8 and a joint slack. Clearly, according to such an embodiment, themotor4 also can drive thebillboard stent2 to rotate, and the structure is more compact and avoids exposing themotor4 and thespeed reducer8 to sun and rain.

In a fifth preferred embodiment of the present invention, as shown inFIG. 13 andFIG. 14, as comparing to the above four preferred embodiment, the rotating table21 is designed to a drum-shaped structure, namely, arotating plate212 connecting with therotating shaft211 aligns with anouter ring213 fixed on the lower surface of therotating plate212 to form a ∩-shaped structure, thepedestal11 comprises alower bottom111 and aninner ring112 corresponding to theouter ring213, wherein theinner ring112 fixed on thelower bottom111 by bolt, therotating element7 is disposed between an inside wall of theouter ring213 and an outside wall of theinner ring112. In order to prevent therotating element7 contacting with dust and prevent the lubricant grease of therotating element7 leaking, anupper sealing element40 is disposed between the inside wall of theouter ring213 and the side surface of thepedestal11, anlower sealing element50 is disposed between the inside wall of theouter ring213 and an side surface of thepedestal11, wherein theupper sealing element40 is upper than therotating element7, thelower sealing element50 is lower than therotating element7, this embodiment is more useful to the rotation of the rotating table21.

One skilled in the art will understand that the embodiment of the present invention as shown in the drawings and described above is exemplary only and not intended to be limiting.

It will thus be seen that the objects of the present invention have been fully and effectively accomplished. It embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.

Claims (18)

1. A stormproof billboard, comprising:

a column, wherein a pedestal is disposed on a top of said column;

a billboard frame, wherein a rotating table is fixed on said billboard frame and corresponding to said pedestal;

a rotating element disposed between said rotating table and said pedestal so as to make said rotating table rotate with respect to said pedestal;

a motor disposed on said column, wherein a driver gear is driven by said motor to rotate said rotating table;

an electromagnetic brake disposed on said column to lock said rotating table;

an anemometer for measuring a wind speed;

a trigger switch disposed between said rotating table and said pedestal to measure that whether said rotating table aligns with said pedestal;

an electric control assembly respectively connecting with said electromagnetic brake, said motor, said anemometer and said trigger switch, wherein said electric control assembly controls working of said motor and said electromagnetic brake by a signal of said trigger switch and a wind speed signal measured by said anemometer; and

a dogvane, wherein said dogvane connects with said electric control assembly to measure an angle D-value, and the angle D-value is a difference value between a billboard frame direction and a natural wind direction.

2. The stormproof billboard, as recited inclaim 1, wherein said trigger switch consists of a block and a limit switch, wherein said limit switch connects with said electric control assembly, said block is fixed on one of said rotating table and said pedestal, while said limit switch is fixed on the other of said rotating table and said pedestal.

3. The stormproof billboard, as recited inclaim 1, wherein said electric control assembly comprises a control element and a signal conversion element, wherein said control element respectively connects with said electromagnetic brake, said motor and said trigger switch, said control element respectively connects with said anemometer and said dogvane by said signal conversion element.

4. The stormproof billboard, as recited inclaim 3, further comprising a forward relay making said motor rotate forward and a backward relay making said motor rotate backward.

5. A control method of said stormproof billboard recited inclaim 4, comprising the steps of:

(31) predetermining an object wind direction scope, a plural continuous design wind direction scope which is greater than the object wind direction scope, a secure wind speed corresponding to each design wind direction scope, a maximal secure wind speed which is less than each secure wind speed, and a delay time;

(32) beginning to collect a first wind speed measured by said anemometer with said electric control assembly;

(33) judging whether the first wind speed is less than the maximal secure wind speed, if not, entering the step (36); if yes, turning on an timer which has been predetermined with the delay time, then entering the next step;

(34) beginning to collect a second wind speed measured by said anemometer with said electric control assembly; judging whether the second wind speed is less than the maximal secure wind speed, if not, said electric control assembly sends the control signal to make said motor lose power, entering the step (36); if yes, judging whether the timer has expired, if not, returning to the step (34), if yes, entering the next step;

(35) judging whether said trigger switch is open, namely, wherein said electric control assembly has received the control signal from said trigger switch, wherein said trigger switch sends the control signal to said electric control assembly when said rotating table has aligned with said pedestal, if not, said electric control assembly sends the control signal to turn on said electromagnetic brake, said forward relay and said backward relay, such that said electromagnetic brake gets power and releases said rotating table so as to make said billboard frame reset under the drive of said motor, resetting the timer, the timer is returned to zero, and returning to the step (34); if yes, said electric control assembly sends the control signal to make said electromagnetic brake and said motor lose power, returning to the step (32);

(36) beginning to collect a first angle D-value with said electric control assembly, comparing the first angle D-value with the object wind direction scope, if the first angle D-value is in the object wind direction scope, said electric control assembly sends the control signal to turn off said electromagnetic brake, such that said electromagnetic brake loses power to lock said rotating table, and returning to the step (32); and

(37) if the first angle D-value is in the design wind direction scope, the first wind speed is greater than or equal to the secure wind speed corresponding to the design wind direction scope, and the first angle D-value is in 0°˜90° or 180°˜270°, sending the control signal to turn on said electromagnetic brake with said electric control assembly, such that said electromagnetic brake gets power and releases said rotating table, and said electric control assembly sends the control signal to turn on said forward relay, such that said billboard frame rotates along the natural wind direction by the drive of said motor, said electric control assembly goes on collecting a second angle D-value until the second angle D-value is 0° or 180°, said motor and said electromagnetic brake are turned off, returning to the step (32); if the first wind speed is greater than or equal to the secure wind speed corresponding to the design wind direction scope, and the first angle D-value is in 90°˜180° or 270°˜360°, sending the control signal to turn on said electromagnetic brake with said electric control assembly, such that said electromagnetic brake gets power and releases said rotating table, and said electric control assembly sends the control signal to turn on said backward relay, such that said billboard frame also rotates along the natural wind direction by the drive of said motor, said electric control assembly goes on collecting a second angle D-value until the second angle D-value is 0° or 180°, said motor and said electromagnetic brake are turned off, returning to the step (32).

6. A control method of said stormproof billboard recited inclaim 1, comprising the steps of:

(21) predetermining a first secure wind speed, a second secure wind speed which is less than the first secure wind speed, a delay time, and an angle-sine translation table stored in said electric control assembly;

(22) beginning to collect a first wind speed measured by said anemometer with said electric control assembly;

(23) judging whether said first wind speed is less than the second secure wind speed, if not, entering the step (26); if yes, turning on an inner timer which has been predetermined with the delay time, then entering the next step;

(24) beginning to collect a second wind speed measured by said anemometer with said electric control assembly; judging whether the second wind speed is less than the second secure wind speed, if not, said electric control assembly sends the control signal to make said motor lose power, entering the step (26); if yes, judging whether the timer has expired, if not, returning to the step (24), if yes, entering the next step;

(25) judging whether said electric control assembly has received the control signal from said trigger switch, wherein said trigger switch sends the control signal to said electric control assembly when said rotating table has aligned with said pedestal, if not, said electric control assembly sends the control signal to turn on said electromagnetic brake and said motor, resetting the timer, the timer is returned to zero, and returning to the step (24); if yes, said electric control assembly sends the control signal to make said electromagnetic brake and said motor lose power so as to make said electromagnetic brake lock said rotating table, returning to the step (22);

(26) beginning to collecting a first angle D-value measured by said dogvane with said electric control assembly, wherein the first angle D-value is a difference value between the billboard direction and the natural wind direction, looking up the sine value of the first angle D-value, the sine value multiplied by the wind speed is a positive wind speed which vertically forces on said billboard frame, judging whether the positive wind speed which vertically forces on said billboard frame is greater than or equal to the first secure wind speed; if yes, said electric control assembly sends the control signal to turn on said electromagnetic brake, entering the next step; if not, returning to the step (22); and

(27) beginning to collecting a second angle D-value measured by said dogvane with said electric control assembly, wherein the second angle D-value is a difference value between the billboard direction and the natural wind direction, judging whether the second angle D-value is zero, if yes, said electric control assembly sends the control signal to turn off said electromagnetic brake, then returning to the step (22); if not, returning to the step (27).

7. A stormproof billboard, comprising:

a column, wherein a pedestal is disposed on a top of said column;

a billboard frame, wherein a rotating table is fixed on said billboard frame and corresponding to said pedestal;

a rotating element disposed between said rotating table and said pedestal so as to make said rotating table rotate with respect to said pedestal;

a motor disposed on said column, wherein a driver gear is driven by said motor to rotate said rotating table;

an electromagnetic brake disposed on said column to lock said rotating table;

an anemometer for measuring a wind speed;

a trigger switch disposed between said rotating table and said pedestal to measure that whether said rotating table aligns with said pedestal; and

an electric control assembly respectively connecting with said electromagnetic brake, said motor, said anemometer and said trigger switch, wherein said electric control assembly controls working of said motor and said electromagnetic brake by a signal of said trigger switch and a wind speed signal measured by said anemometer; wherein a rotating shaft downwards inserting into said column is disposed on said rotating table, said electromagnetic brake is disposed in said column, said electromagnetic brake comprises a braked wheel ringing on said rotating shaft, a left friction plate disposed on a left side of said braked wheel, and a right friction plate disposed on a right side of said braked wheel, wherein one end of each of said left friction plate and said right friction plate is fixed on an inside wall of said column respectively, another end of each of said left friction plate and said right friction plate is free, and two electromagnetic power units are respectively disposed on said free ends of said left friction plate and said right friction plate.

8. The stormproof billboard, as recited inclaim 7, wherein a center current collector is disposed in said column, said center current collector comprises at least an electric elastic clip, and a collecting ring fixed on said rotating shaft, wherein two carbon brushes are respectively fixed on two relative ends of said elastic clips, a plurality of electric annular grooves are spacedly formed on said collecting ring and are mutually insulating, each electric annular groove of said collecting ring is clipped by said corresponding elastic clip to make said carbon brushes cling to an outside surface of said electric annular groove.

9. The stormproof billboard, as recited inclaim 8, wherein said electric control assembly comprises a control element and a signal conversion element, wherein said control element respectively connects with said electromagnetic brake, said motor and said trigger switch, said control element respectively connects with said anemometer and said dogvane by said signal conversion element.

10. The stormproof billboard, as recited inclaim 9, further comprising a forward relay making said motor rotate forward and a backward relay making said motor rotate backward.

11. A control method of said stormproof billboard recited inclaim 10, comprising the steps of:

(31) predetermining an object wind direction scope, a plural continuous design wind direction scope which is greater than the object wind direction scope, a secure wind speed corresponding to each design wind direction scope, a maximal secure wind speed which is less than each secure wind speed, and a delay time;

(32) beginning to collect a first wind speed measured by said anemometer with said electric control assembly;

(33) judging whether the first wind speed is less than the maximal secure wind speed, if not, entering the step (36); if yes, turning on an timer which has been predetermined with the delay time, then entering the next step;

(34) beginning to collect a second wind speed measured by said anemometer with said electric control assembly; judging whether the second wind speed is less than the maximal secure wind speed, if not, said electric control assembly sends the control signal to make said motor lose power, entering the step (36); if yes, judging whether the timer has expired, if not, returning to the step (34), if yes, entering the next step;

(35) judging whether said trigger switch is open, namely, wherein said electric control assembly has received the control signal from said trigger switch, wherein said trigger switch sends the control signal to said electric control assembly when said rotating table has aligned with said pedestal, if not, said electric control assembly sends the control signal to turn on said electromagnetic brake, said forward relay and said backward relay, such that said electromagnetic brake gets power and releases said rotating table so as to make said billboard frame reset under the drive of said motor, resetting the timer, the timer is returned to zero, and returning to the step (34); if yes, said electric control assembly sends the control signal to make said electromagnetic brake and said motor lose power, returning to the step (32);

(36) beginning to collect a first angle D-value with said electric control assembly, comparing the first angle D-value with the object wind direction scope, if the first angle D-value is in the object wind direction scope, said electric control assembly sends the control signal to turn off said electromagnetic brake, such that said electromagnetic brake loses power to lock said rotating table, and returning to the step (32); and

(37) if the first angle D-value is in the design wind direction scope, the first wind speed is greater than or equal to the secure wind speed corresponding to the design wind direction scope, and the first angle D-value is in 0°˜90° or 180°˜270°, sending the control signal to turn on said electromagnetic brake with said electric control assembly, such that said electromagnetic brake gets power and releases said rotating table, and said electric control assembly sends the control signal to turn on said forward relay, such that said billboard frame rotates along the natural wind direction by the drive of said motor, said electric control assembly goes on collecting a second angle D-value until the second angle D-value is 0° or 180°, said motor and said electromagnetic brake are turned off, returning to the step (32); if the first wind speed is greater than or equal to the secure wind speed corresponding to the design wind direction scope, and the first angle D-value is in 90°˜180° or 270°˜360°, sending the control signal to turn on said electromagnetic brake with said electric control assembly, such that said electromagnetic brake gets power and releases said rotating table, and said electric control assembly sends the control signal to turn on said backward relay, such that said billboard frame also rotates along the natural wind direction by the drive of said motor, said electric control assembly goes on collecting a second angle D-value until the second angle D-value is 0° or 180°, said motor and said electromagnetic brake are turned off, returning to the step (32).

12. The stormproof billboard, as recited inclaim 8, wherein said trigger switch consists of a block and a limit switch, wherein said limit switch connects with said electric control assembly, said block is fixed on one of said rotating table and said pedestal, while said limit switch is fixed on the other of said rotating table and said pedestal.

13. The stormproof billboard, as recited inclaim 7, wherein said trigger switch consists of a block and a limit switch, wherein said limit switch connects with said electric control assembly, said block is fixed on one of said rotating table and said pedestal, while said limit switch is fixed on the other of said rotating table and said pedestal.

14. The stormproof billboard, as recited inclaim 7, wherein said electric control assembly comprises a control element and a signal conversion element, wherein said control element respectively connects with said electromagnetic brake, said motor and said trigger switch, said control element respectively connects with said anemometer and said dogvane by said signal conversion element.

15. The stormproof billboard, as recited inclaim 14, further comprising a forward relay making said motor rotate forward and a backward relay making said motor rotate backward.

16. A control method of said stormproof billboard recited inclaim 15, comprising the steps of:

(31) predetermining an object wind direction scope, a plural continuous design wind direction scope which is greater than the object wind direction scope, a secure wind speed corresponding to each design wind direction scope, a maximal secure wind speed which is less than each secure wind speed, and a delay time;

(32) beginning to collect a first wind speed measured by said anemometer with said electric control assembly;

(33) judging whether the first wind speed is less than the maximal secure wind speed, if not, entering the step (36); if yes, turning on an timer which has been predetermined with the delay time, then entering the next step;

(34) beginning to collect a second wind speed measured by said anemometer with said electric control assembly; judging whether the second wind speed is less than the maximal secure wind speed, if not, said electric control assembly sends the control signal to make said motor lose power, entering the step (36); if yes, judging whether the timer has expired, if not, returning to the step (34), if yes, entering the next step;

(35) judging whether said trigger switch is open, namely, wherein said electric control assembly has received the control signal from said trigger switch, wherein said trigger switch sends the control signal to said electric control assembly when said rotating table has aligned with said pedestal, if not, said electric control assembly sends the control signal to turn on said electromagnetic brake, said forward relay and said backward relay, such that said electromagnetic brake gets power and releases said rotating table so as to make said billboard frame reset under the drive of said motor, resetting the timer, the timer is returned to zero, and returning to the step (34); if yes, said electric control assembly sends the control signal to make said electromagnetic brake and said motor lose power, returning to the step (32);

(36) beginning to collect a first angle D-value with said electric control assembly, comparing the first angle D-value with the object wind direction scope, if the first angle D-value is in the object wind direction scope, said electric control assembly sends the control signal to turn off said electromagnetic brake, such that said electromagnetic brake loses power to lock said rotating table, and returning to the step (32); and

(37) if the first angle D-value is in the design wind direction scope, the first wind speed is greater than or equal to the secure wind speed corresponding to the design wind direction scope, and the first angle D-value is in 0°˜90° or 180°˜270°, sending the control signal to turn on said electromagnetic brake with said electric control assembly, such that said electromagnetic brake gets power and releases said rotating table, and said electric control assembly sends the control signal to turn on said forward relay, such that said billboard frame rotates along the natural wind direction by the drive of said motor, said electric control assembly goes on collecting a second angle D-value until the second angle D-value is 0° or 180°, said motor and said electromagnetic brake are turned off, returning to the step (32); if the first wind speed is greater than or equal to the secure wind speed corresponding to the design wind direction scope, and the first angle D-value is in 90°˜180° or 270°˜360°, sending the control signal to turn on said electromagnetic brake with said electric control assembly, such that said electromagnetic brake gets power and releases said rotating table, and said electric control assembly sends the control signal to turn on said backward relay, such that said billboard frame also rotates along the natural wind direction by the drive of said motor, said electric control assembly goes on collecting a second angle D-value until the second angle D-value is 0° or 180°, said motor and said electromagnetic brake are turned off, returning to the step (32).

17. A stormproof billboard, comprising:

a column, wherein a pedestal is disposed on a top of said column;

a billboard frame, wherein a rotating table is fixed on said billboard frame and corresponding to said pedestal;

a rotating element disposed between said rotating table and said pedestal so as to make said rotating table rotate with respect to said pedestal;

a motor disposed on said column, wherein a driver gear is driven by said motor to rotate said rotating table;

an electromagnetic brake disposed on said column to lock said rotating table;

an anemometer for measuring a wind speed;

a trigger switch disposed between said rotating table and said pedestal to measure that whether said rotating table aligns with said pedestal; and

an electric control assembly respectively connecting with said electromagnetic brake, said motor, said anemometer and said trigger switch, wherein said electric control assembly controls working of said motor and said electromagnetic brake by a signal of said bidder switch and a wind speed signal measured by said anemometer,

wherein said trigger switch consists of a block and a limit switch, wherein said limit switch connects with said electric control assembly, said block is fixed on one of said rotating table and said pedestal, while said limit switch is fixed on the other of said rotating table and said pedestal.

18. A control method of a stormproof billboard,

wherein said stormproof billboard comprises:

a column, wherein a pedestal is disposed on a top of said column;

a billboard frame, wherein a rotating table is fixed on said billboard frame and corresponding to said pedestal;

a rotating element disposed between said rotating table and said pedestal so as to make said rotating table rotate with respect to said pedestal;

a motor disposed on said column, wherein a driver gear is driven by said motor to rotate said rotating table;

an electromagnetic brake disposed on said column to lock said rotating table;

an anemometer for measuring a wind speed;

a trigger switch disposed between said rotating table and said pedestal to measure that whether said rotating table aligns with said pedestal; and

an electric control assembly respectively connecting with said electromagnetic brake, said motor, said anemometer and said trigger switch, wherein said electric control assembly controls working of said motor and said electromagnetic brake by a signal of said trigger switch and a wind speed signal measured by said anemometer,

comprising the steps of:

(11) predetermining a first secure wind speed, a second secure wind speed which is less than the first secure wind speed, and a delay time;

(12) beginning to collect a first wind speed measured by said anemometer with said electric control assembly;

(13) judging whether the first wind speed is greater than or equal to the first secure wind speed, if not, returning to the step (12); if yes, said electric control assembly sends a control signal to turn on said electromagnetic brake, such that said electromagnetic brake gets power and releases said rotating table so as to make said billboard frame rotate with the natural wind, then entering the next step;

(14) beginning to collect a second wind speed measured by said anemometer with said electric control assembly;

(15) judging whether the second wind speed is greater than or equal to the first secure wind speed, if yes, returning to the step (14); if not, entering the next step;

(16) judging whether the second wind speed is less than the second secure wind speed, if not, returning to the step (14); if yes, turning on an inner timer which has been predetermined with the delay time, then entering the next step;

(17) beginning to collect a third wind speed measured by said anemometer with said electric control assembly;

(18) judging whether the third wind speed is less than the second secure wind speed, if not, returning to the step (14); if yes, judging whether the timer has expired, if not, returning to the step (17), if yes, entering the next step; and

(19) judging whether said electric control assembly has received the control signal from said trigger switch, wherein said trigger switch sends the control signal to said electric control assembly when said rotating table has aligned with said pedestal, if not, said electric control assembly continues sending the control signal to turn on said electromagnetic brake and said motor, such that said electromagnetic brake continues to release said rotating table so as to make said billboard frame reset by the drive of said motor; if yes, said electric control assembly sends the control signal to make said electromagnetic brake and said motor lose power so as to make said electromagnetic brake lock said billboard frame, returning to the step (12).

Images